1. Field of the Invention
The present invention relates to a surgical instrument for use in a surgical operation in which an end effector disposed on a distal end of the surgical instrument is operated by a human operator by manipulating a handle disposed on a proximal end of an insertion portion of the surgical instrument. More particularly, the present invention relates to a surgical instrument for use in endoscopic surgery.
2. Description of the Related Art
Conventionally, an endoscope is widely used to perform various surgical treatments on a body tissue while observing an image of the body tissue via the endoscope having an elongated insertion portion inserted in a body cavity. In recent years, endoscopes have been used to perform surgical treatments or procedures without having to perform a laparotomy and thus without imposing significant invasion against patients. In such endoscopic surgery, an endoscope for observation is introduced into a body cavity via a trocar, and a surgical instrument is introduced to a portion of interest in the body cavity via the trocar. While observing the surgical instrument and the portion of interest via the endoscope, a surgical treatment or procedure is performed.
Surgical instruments used in endoscopic surgery or the like are formed in an elongated shape, and an end effector disposed on an end of an insertion portion is manipulated by handling an operation control portion disposed on the opposite end.
A surgical instrument capable of rotating its end effector disposed on an end of an insertion portion is disclosed, for example, in U.S. Pat. Nos. 5,275,608, 5,330,502, 5,383,888, or 5,549,637.
More specifically, in a surgical instrument disclosed in U.S. Pat. No. 5,275,608, an end effector disposed on a distal end can be opened and closed by opening and closing a pair of handles disposed on a proximal end of the surgical instrument, and the end effector can be pivoted, that is, the orientation of the end effector can be changed, by rotating the pair of handles.
In a surgical instrument disclosed in U.S. Pat. No. 5,330,502, a treatment tool disposed on its distal end part can be opened and closed, and the distal end part can be pivoted in a direction away from the main axis of the treatment tool. In this surgical instrument, to realize the above capabilities, a rotation knob for rotating the distal end about the main axis is disposed at a location in front part of an operation handle, and a pivot control knob for pivoting the distal end part of the surgical instrument is disposed next to the rotation knob.
In a surgical instrument disclosed in U.S. Pat. No. 5,383,888, an end effector can be opened and closed by opening and closing a pair of handles disposed on the proximal end of the surgical instrument. Furthermore, in this surgical instrument, the end effector can be pivoted by operating a pivot control portion disposed on the proximal end.
In a surgical instrument disclosed in U.S. Pat. No. 5,549,637, a treatment tool attached to a distal end part of the surgical instrument can be operated. Furthermore, the distal end part can be pivoted in a direction away from the main axis of the treatment tool, and the treatment tool attached to the distal end part can be rotated about the axis independently. In this surgical instrument, the treatment tool is manipulated via a rigid base-side rod, a link substantially passing though a rotatable joint, and a head-side rod. Furthermore, in this surgical instrument, a rotation knob for rotating the main shaft is disposed in front part of the operation handle, at a distal-end side, to a manipulation handle, a pivot control knob is disposed next to the rotation control knob, and a rotation knob for independently rotating the treatment tool is disposed next to the pivot control knob.